Journal Article

Neural correlates of water reward in thirsty Drosophila

Lin, Suewei, Chandra, Vikram, Waddell, Scott, Talbot, Clifford, Owald, David, Huetteroth, Wolf

2014

Overview

Using the Drosophila system, this study shows that rewarding and motivational properties of water are mediated by different subsets of dopaminergic neurons. The study also shows a satiety state–dependent effect in which thirst can change water avoidance behavior into water-seeking behavior and demonstrates that water wanting versus liking versus learning are separable at the level of behavior and the underlying neural circuit. Drinking water is innately rewarding to thirsty animals. In addition, the consumed value can be assigned to behavioral actions and predictive sensory cues by associative learning. Here we show that thirst converts water avoidance into water-seeking in naive Drosophila melanogaster . Thirst also permitted flies to learn olfactory cues paired with water reward. Water learning required water taste and <40 water-responsive dopaminergic neurons that innervate a restricted zone of the mushroom body γ lobe. These water learning neurons are different from those that are critical for conveying the reinforcing effects of sugar. Naive water-seeking behavior in thirsty flies did not require water taste but relied on another subset of water-responsive dopaminergic neurons that target the mushroom body β′ lobe. Furthermore, these naive water-approach neurons were not required for learned water-seeking. Our results therefore demonstrate that naive water-seeking, learned water-seeking and water learning use separable neural circuitry in the brain of thirsty flies.

• Publisher: Nature Publishing Group US,Nature Publishing Group
• Subject: 631/378/1595 / Animal Genetics and Genomics / Animals / Behavioral Sciences / Biological Techniques / Biomedicine / Conditioning, Classical - physiology / Dopaminergic Neurons - metabolism / Drinking (Physiology) / Drosophila / Drosophila melanogaster / Drosophila melanogaster - physiology / Foraging behavior / Insects / Learning / Memory / Memory - physiology / Mushroom Bodies - innervation / Mushroom Bodies - physiology / Neural circuitry / Neurobiology / Neurosciences / Observations / Physiological aspects / Psychological aspects / Reinforcement, Psychology / Reward / Thirst - physiology / Valuation / Water - physiology